I own many S&W's but only have fired OP's redhawks. My non-technical impression was the Ruger had an aweful trigger and I wondered why anyone would own one compared to a smooth S&W. It did feel like it was built like a tank though.

I would refer you to an excellent article in the April 2010 issue of Handloader magazine where Brian Pierce writes an excellent article on handloading +P 44 mags. In this test, he uses the Ruger redhawk as the test platform and details why this gun can take loads other guns (S&W,etc) cannot. He lists sereral clever aspects of the Ruger design that give it an upper hand in the durability department. Some are:

1) Offset Cyl stop notches in relation to chamber's
2) Offset ejector rod to the frame axis increasing frame strength in the barrel receiver area. More steel supports the barrel shank.
3)Outside chamber walls measure .115 inch
4)Cyl lock at front of crane and rear of cyl.
5)lockwork that drops down out of the frame leaving it free of sideplates adding rigidity.
6)Outside Cyl dimension at a large 1.7805

To sum it up, the Ruger has a definite durability advantage, but I think the Smith will have a superior trigger and more refinement. Comparative accuracy is probably harder to distinguish, although I'd put my money on S&W. It all boils down to what you want out of your gun. With normal loads, I think either gun will outlast you.

IC